Postoperative venous thromboembolism in advanced epithelial ovarian cancer: risk factors, tumor gene expression, and survival

Objective Epithelial ovarian cancer is related to increased incidence of venous thromboembolism. In a clinical single-center cohort study, we investigated risk factors for postoperative venous thromboembolism, prognostic factors, and the association of venous thromboembolism with tumor-tissue transcriptome. Methods This cohort consisted of 200 stage III-IV ovarian cancer patients referred to Helsinki University Hospital for primary or interval debulking surgery during 2021-2024. We collected data on patient characteristics, coagulation biomarkers, surgical details, postoperative venous thromboembolism and survival, and RNA sequencing of tumor tissue from venous thromboembolism patients and matched controls. Results Of the 200 patients 125 underwent primary and 75 interval surgery. High-grade serous carcinoma was the dominant histology type. Preoperative fibrinogen, coagulation factor VIII, and D-dimer were above normal range and correlated with inflammation. The incidence of venous thromboembolism was 13.6% in the primary surgery and 2.7% in the interval surgery group (p=0.012), despite 31% of patients having preoperative anticoagulation. Also, duration of operation and liver mobilization were risk factors for venous thromboembolism, while perioperative red blood cell transfusions to manage bleeding events seemed protective. Low albumin was negatively associated with overall survival. Tumor RNA sequencing identified increased oxidative stress related genes, and reduced expression of genes linked to anti-inflammatory regulation, which may contribute to venous thromboembolism risk. Conclusions Thromboinflammatory phenotype in blood is common in ovarian cancer. Primary surgery and the extent of surgery are associated with postoperative venous thromboembolism, while perioperative red blood cell transfusions have a protective association. Albumin serves as a prognostic biomarker.